protected UnlaunchFeature GetFeature(string flagKey, string identity, IEnumerable <UnlaunchAttribute> attributes)
{
if (!_flagMap.ContainsKey(flagKey))
{
throw new Exception("Flag doesn't exist");
}
var user = attributes == null?UnlaunchUser.Create(identity) : UnlaunchUser.CreateWithAttributes(identity, attributes);
return(Evaluator.Evaluate(_flagMap[flagKey], user));
}
private UnlaunchFeature Evaluate(string flagKey, string identity, IEnumerable <UnlaunchAttribute> attributes)
{
if (string.IsNullOrEmpty(flagKey))
{
throw new ArgumentException("flagKey must not be null or empty");
}
if (string.IsNullOrWhiteSpace(identity))
{
throw new ArgumentException($"userId must be a string and cannot contain any whitespace characters: {identity}");
}
if (_shutdownInitiated.Get())
{
Logger.Debug($"Asked to evaluate flag {flagKey} but shutdown already initiated on the client");
return(UnlaunchConstants.GetControlFeatureByName(flagKey));
}
if (!IsReady())
{
Logger.Warn("the SDK is not ready. Returning the SDK default 'control' as variation which may not give the right result");
return(UnlaunchConstants.GetControlFeatureByName(flagKey));
}
var user = attributes == null?UnlaunchUser.Create(identity) : UnlaunchUser.CreateWithAttributes(identity, attributes);
FeatureFlag flag;
try
{
flag = _dataStore.GetFlag(flagKey);
}
catch (Exception e)
{
return(new UnlaunchFeature(flagKey, UnlaunchConstants.FlagDefaultReturnType,
null, $"there was an error fetching flag: {e.Message}"));
}
if (flag == null)
{
Logger.Warn($"UnlaunchFeature '{flagKey}' not found in the data store. Returning 'control' variation");
return(new UnlaunchFeature(flagKey, UnlaunchConstants.FlagDefaultReturnType,
null, "flag was not found in the in-memory cache"));
}
var result = _evaluator.Evaluate(flag, user);
var impression = new Impression
{
type = UnlaunchConstants.EventTypeForImpressionEvents,
key = flag.Key,
secondaryKey = result.GetVariation(),
flagKey = flag.Key,
flagStatus = flag.Enabled.ToString(),
evaluationReason = result.GetEvaluationReason(),
userId = user.GetId(),
variationKey = result.GetVariation()
};
Track(impression);
return(result);
}
